Linking problems with yaml-cpp - cmake

Question

I am trying to incorporate yaml-cpp into my project.
I have a "Demes" class where I need to parse a YAML file.
This is the relevant method in Demes.cpp:
#include "Demes.hpp"
void Demes::parse(const std::string& fileName)
{
YAML::Node test = YAML::LoadFile(fileName);
}
where Demes.hpp includes the yaml-cpp headers and declares the 'parse' method.
Building with make -VERBOSE=1 (as suggested by #Tsyvarev) gives:
[100%] Linking CXX executable momentspp
cd /home/gvbarroso/Devel/momentspp/build/src && /usr/bin/cmake -E cmake_link_script CMakeFiles/momentspp.dir/link.txt --verbose=1
/usr/bin/c++ -std=c++20 -Weffc++ -Wshadow -Wall -Wextra -ffast-math -O3 -march=native CMakeFiles/momentspp.dir/Log.cpp.o CMakeFiles/momentspp.dir/PolymorphismData.cpp.o CMakeFiles/momentspp.dir/SumStatsLibrary.cpp.o CMakeFiles/momentspp.dir/Drift.cpp.o CMakeFiles/momentspp.dir/Migration.cpp.o CMakeFiles/momentspp.dir/Mutation.cpp.o CMakeFiles/momentspp.dir/Recombination.cpp.o CMakeFiles/momentspp.dir/Epoch.cpp.o CMakeFiles/momentspp.dir/Model.cpp.o CMakeFiles/momentspp.dir/OptimizationWrapper.cpp.o CMakeFiles/momentspp.dir/Demes.cpp.o CMakeFiles/momentspp.dir/main.cpp.o -o momentspp -Wl,-rpath,/home/gvbarroso/.local/lib: /home/gvbarroso/.local/lib/libbpp-phyl3.so.1.0.0 /usr/lib/x86_64-linux-gnu/libboost_iostreams.so.1.74.0 /home/gvbarroso/.local/lib/libbpp-seq3.so.1.0.0 /home/gvbarroso/.local/lib/libbpp-core3.so.1.0.0
/usr/bin/ld: CMakeFiles/momentspp.dir/Demes.cpp.o: in function Demes::parse(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': Demes.cpp:(.text+0x4c): undefined reference to YAML::LoadFile(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&)'
/usr/bin/ld: Demes.cpp:(.text+0x12c): undefined reference to `YAML::operator<<(std::ostream&, YAML::Node const&)'
collect2: error: ld returned 1 exit status
make[2]: *** [src/CMakeFiles/momentspp.dir/build.make:277: src/momentspp] Error 1
make[2]: Leaving directory '/home/gvbarroso/Devel/momentspp/build'
make[1]: *** [CMakeFiles/Makefile2:125: src/CMakeFiles/momentspp.dir/all] Error 2
make[1]: Leaving directory '/home/gvbarroso/Devel/momentspp/build'
make: *** [Makefile:156: all] Error 2
I am using CMake to build my project, but I am still fairly unfamiliar with it.
EDIT: I forgot to mention that I have two CMakeLists.txt files, one inside src and the other inside the external build.
The start of my CMakeLists.txt file in the external build is:
cmake_minimum_required (VERSION 3.5.0)
project (momentspp CXX)
SET(CMAKE_CXX_FLAGS "-std=c++20 -Weffc++ -Wshadow -Wall -Wextra -ffast-math -O3 -march=native")
And the part of it where I look for yaml-cpp is:
FIND_PACKAGE(yaml-cpp REQUIRED)
IF(yaml-cpp_FOUND)
INCLUDE_DIRECTORIES(${yaml-cpp_INCLUDE_DIRS})
SET(LIBS {yaml-cpp_LIBRARIES})
MESSAGE("-- yaml-cpp libraries found here:")
MESSAGE(" includes: ${yaml-cpp_INCLUDE_DIRS}")
ENDIF()
My full CMakeLists.txt file inside src is:
SET(momentspp_CPP
Log.cpp
PolymorphismData.cpp
SumStatsLibrary.cpp
Drift.cpp
Migration.cpp
Mutation.cpp
Recombination.cpp
Epoch.cpp
Model.cpp
OptimizationWrapper.cpp
Demes.cpp
main.cpp
)
ADD_EXECUTABLE (momentspp ${momentspp_CPP})
SET(momentspp-targets momentspp)
FOREACH (target ${momentspp-targets})
TARGET_LINK_LIBRARIES(${target} ${BPP_LIBS_SHARED} ${BOOST_LIBS_SHARED} ${EIGEN3_LIBS_SHARED} ${yaml-cpp_LIBS_SHARED})
TARGET_LINK_LIBRARIES (${target} ${LIBS})
ENDFOREACH (target)
INSTALL(TARGETS ${momentspp-targets} DESTINATION ${CMAKE_INSTALL_BINDIR})
and this was working prior to the inclusion of yaml-cpp.
This feels like a rather complicated CMake set-up, but I am copying and editing it from a previous project where someone else helped me with it.
How can I fix the linking issue?
I tried looking similar questions around here, but couldn't get their solutions to work for me (apparently those people where not using CMake to build their projects).
Thank you,
Gustavo